Image forming device

ABSTRACT

When an image memory ( 106 ) may be full during facsimile reception, and an image processing section ( 314 ) causes a printer section ( 6 ) to currently perform a copying operation, the copying operation is interrupted, and facsimile reception is continued while reading out reception image data in the chronological order and performing printing, thereby avoiding a memory full state of the image memory ( 106 ) and preventing line disconnection.

TECHNICAL FIELD

The present invention relates to an image forming apparatus having,e.g., a facsimile function and a copying function and, moreparticularly, to an image forming apparatus having a function of issuingreception image data printing start request when the remaining capacityof a reception image memory for storing image data received by facsimilehas a predetermined value or less, and detecting at this time whetherpaper jam has occurred and whether a copying operation has beenperformed.

BACKGROUND ART

To effectively use the printer resource for a printing job, an imageforming apparatus having a facsimile function and a copying function hasa function of temporarily storing facsimile image data in an imagememory to prevent a document being subjected to facsimile communicationfrom occupying the printer, and sequentially transferring the storedimage data to a page memory and printing it.

In a communication protocol generally used for a facsimile apparatus,reception completion is returned to the transmission side. To guaranteethis, preferably, printing of received image data is started before theimage memory for storing received image data becomes full, therebyeffectively using the reception image memory and preventing a linedisconnection state due to the memory full state.

As far as all transmitted image data are stored in the image memory,even power is turned off or paper jam occurs during printing a receiveddocument and image data transferred from the image memory to the pagememory is lost, the image data can be read out from the image memoryagain after power is restored or paper jam is eliminated, so no problemis posed.

In an image forming apparatus having a facsimile function, facsimileimage data to be transmitted is temporarily stored in an image memory bytransmission reservation. However, the memory may become full. To allowthe facsimile reception even in this case, an exclusive reception areais formed in the image memory. However, even this exclusive receptionarea may become full during storage reception.

When this exclusive reception area becomes full during the storagereception, the former received image is transferred to the page memorywhile being developed, printing is executed, and just received imagedata is continuously overwritten in a printing completion area, therebycontinuing reception without any interruption. However, the facsimilereception image data cannot sometimes be printed because paper jam hasalready occurred or because a copying operation has been performed. Inthe paper jam state, printing cannot be performed. Conventionally, evenduring the copying operation, the copying operation has priority overthe facsimile operation, and facsimile reception image data cannot beprinted. Hence, the image memory for facsimile reception often becomesfull, resulting in a disadvantage such as line disconnection.

For example, FIG. 12 of Jpn. Pat. Appln. KOKAI Publication No. 5-284265shows an apparatus having two printers, in which when a FAX function isperformed, reception data by the FAX interface section is stored not ina memory on the FAX side but in a memory on the system controller side.

However, the apparatus of this prior art has two printers and istherefore complex and expensive. In addition, when the memory forstoring FAX reception data becomes full, the FAX reception line isdisconnected.

It is therefore an object of the present invention to provide aconvenient image forming apparatus, which can print a facsimilereception image even during a copying operation when a facsimilereception image memory becomes full and minimizes line disconnection.

DISCLOSURE OF INVENTION

An image forming apparatus of the present invention is characterized bycomprising a reception image memory for storing reception image data,means for checking whether a printing operation using the receptionimage data stored in the reception image memory can be started when aremaining capacity of the reception image memory has not more than apredetermined value, means for starting printing using the receptionimage data when it is determined by the checking means that printing ispossible, means for, when a printing disable state is detected by thechecking means, displaying the printing disable state and checkingwhether a cause is paper jam, and means for, when the cause is paperjam, causing the reception image memory to continuously receive andstore the reception image data.

An image forming apparatus characterized by further comprising, inaddition to the above arrangement, interruption designation means for,during an operation of a copying means, designating to interrupt theoperation, and means for printing the reception image data in responseto the interruption designation.

The apparatus is characterized by further comprising means for causingthe copying means to resume the interrupted printing when printing ofthe reception image data is completed.

According to the present invention, an image forming apparatus in animage data transmission/reception system including first and secondapparatuses having reading means, connected to each other through acommunication line, for reading originals and converting an readoriginal signal into image data, transmission means for transmittingimage data read from the originals, reception means for receiving theimage data, and image forming means for forming images of the image dataon a target image forming medium, characterized in that each of thefirst and second apparatuses comprises a reception image memory forstoring reception image data, means for checking whether a printingoperation using the reception image data stored in the reception imagememory can be started when a remaining capacity of the reception imagememory has not more than a predetermined value, means for startingprinting using the reception image data when it is determined by thechecking means that printing is possible, means for, when a printingdisable state is detected by the checking means, displaying the printingdisable state and checking whether a cause is paper jam or an operationof copying means, means for, when the cause is paper jam, causing thereception image memory to continuously receive and store the receptionimage data, interruption designation means for, when the cause is theoperation of the copying means, designating interruption, and means forprinting the reception image data in response to the interruptiondesignation.

According to the present invention, a convenient image forming apparatuswhich allows an interrupt for printing facsimile reception image dataeven when a copying operation is being performed in the memory fullstate of a facsimile reception image memory, and switches the job topreferentially print the facsimile reception image data can be provided.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a view showing the schematic arrangement of an image formingapparatus according to an embodiment of the present invention.

FIG. 2 is a plan view of an operation panel arranged on the imageforming apparatus shown in FIG. 1.

FIG. 3 is an enlarged view of some operation keys shown in FIG. 2.

FIG. 4 is a block diagram showing the functional arrangement of theimage forming apparatus shown in FIG. 1.

FIG. 5 is a block diagram showing the internal arrangement of a basiccontrol section shown in FIG. 4.

FIG. 6 is a view showing the internal arrangement of an image memoryshown in FIG. 5.

FIG. 7 is a flow chart showing the operation of the image formingapparatus having the arrangement. shown in FIGS. 1 to 6.

FIG. 8 is a flow chart showing the operation of the image formingapparatus having the arrangement shown in FIGS. 1 to 6.

FIGS. 9A to 9C are views showing the relationship between the imagememory and a page memory in association with memory contents.

FIG. 10 is a flow chart showing the contents of the start of memoryreception.

FIG. 11 is flow chart showing the start of transfer of image data fromthe image memory to the page memory.

FIG. 12 is a flow chart showing the start of printing.

FIG. 13 is a flow chart showing memory over processing.

FIG. 14 is a flow chart showing the operation of the embodiment of thepresent invention.

FIG. 15 is a flow chart showing the operation of a facsimile CPU in FIG.14 in detail.

FIG. 16 is a flow chart of the operation of a printer CPU for receivinga printing request issued in FIG. 15.

FIG. 17 is a flow chart of the operation of a printer CPU for receivinga printing request issued in FIG. 16.

BEST MODE FOR CARRYING OUT INVENTION

An image forming apparatus according to an embodiment of the presentinvention will be described below with reference to the accompanyingdrawings. This image forming apparatus is constituted as a copyingmachine having a facsimile function.

The internal structure of this copying machine will be described withreference to the schematic view shown in FIG. 1.

As shown in FIG. 1, a copying machine 1 has an apparatus main body 10.The apparatus main body 10 incorporates a scanner section 4 functioningas a reading means and a printer section 6 functioning as an imageforming means (both will be described later).

An original table 12 formed from transparent glass, on which a readobject, i.e., an original D for facsimile transmission or copy isplaced, is arranged on the upper surface of the apparatus main body 10.An automatic document feeder 7 (to be referred to as an ADF hereinafter)for automatically feeding originals onto the original table 12 isdisposed on the upper surface of the apparatus main body 10. The ADF 7is arranged to be opened/closed with respect to the original table 12and also functions as an original cover for bringing the original Dplaced on the original table 12 into tight contact with the originaltable 12.

The ADF 7 has an original tray 8 on which the original D is set, anempty sensor 9 for detecting the presence/absence of originals, pickuprollers 14 for extracting originals on the original tray 8 one by one, afeed roller 15 for conveying the extracted original, an aligning rollerpair 16 for aligning the leading edges of the originals, and a conveyorbelt 18 arranged to cover almost the entire surface of the originaltable 12.

A plurality of originals set on the original tray 8 with their surfacesfacing up are sequentially extracted from the lowermost page, i.e., thefinal page, aligned by the aligning roller pair 16, and conveyed to apredetermined position on the original table 12 by the conveyor belt 18.

In the ADF 7, a reversing roller 20, a non-reverse sensor 21, a flapper22, and a delivery roller 23 are disposed at the end portion on theopposite side of the aligning roller pair 16 with respect to theconveyor belt 18.

The original D whose image information is read by the scanner section 4(to be described later) is fed from the original table 12 by theconveyor belt 18 and delivered to an original delivery portion 24 on theADF 7 through the reversing roller 20, flapper 21, and delivery roller22.

To read the lower surface of the original D, the flapper 22 is switched.The original D conveyed by the conveyor belt 18 is reversed by thereversing roller 20 and fed to a predetermined position on the originaltable 12 again by the conveyor belt 18.

The scanner section 4 incorporated in the apparatus main body 10 has anexposure lamp 25 as a light source of illuminating the original D placedon the original table 12, and a first mirror 26 for deflecting reflectedlight from the original D in a predetermined direction. The exposurelamp 25 and first mirror 26 are attached to a first carriage 27 disposedunder the original table 12.

The first carriage 27 is disposed to be movable in parallel to theoriginal table 12 and reciprocally moved under the original table 12 bya driving motor through a toothed belt (not shown).

A second carriage 28 movable in parallel to the original table 12 isdisposed under the original table 12. Second and third mirrors 30 and 31for sequentially deflecting reflected light from the original D, whichis deflected by the first mirror 26, are attached to the second carriage28 so as to make a right angle. The second carriage 28 is moved by,e.g., the toothed belt for driving the first carriage 27 together withthe first carriage 27, and moved in parallel along the original table 12at a speed 1/2 that of the first carriage.

An imaging lens 32 for focusing reflected light from the third mirror 31mounted on the second carriage 28, and a CCD sensor 34 for receiving thereflected light focused by the imaging lens and photoelectricallyconverting it are also disposed under the original table 12. The imaginglens 32 is disposed to be movable through a driving mechanism in a planeincluding the optical axis of the light deflected by the third mirror31, and forms the image of the reflected light at a desiredmagnification by moving itself. The CCD sensor 34 photoelectricallyconverts the incoming reflected light and outputs an electrical signalcorresponding to the read original D.

On the other hand, the printer section 6 has a laser exposure apparatus40 functioning as a latent image forming means. The laser exposureapparatus 40 comprises a semiconductor laser 41 as a light source, apolygon mirror 36 as a scanning member for continuously deflecting alaser beam emitted by the semiconductor laser 41, a polygon motor 37 asa scanning motor for rotatably driving the polygon mirror 36 at apredetermined rotational speed (to be described later), and an opticalsystem 42 for deflecting the laser beam from the polygon mirror andguiding the beam to a photosensitive drum 44 (to be described later).The laser exposure apparatus 40 having the above arrangement ispermanently fixed on a support frame (not shown) of the apparatus mainbody 10.

The semiconductor laser 41 is ON/OFF-controlled in accordance with theimage information of the original D read by the scanner section 4 orfacsimile transmission/reception document information. The laser beam isdirected to the photosensitive drum 44 through the polygon mirror 36 andoptical system 42 to scan the outer surface of the photosensitive drum44, thereby forming an electrostatic latent image on the outer surfaceof the photosensitive drum 44.

The printer section 6 has the rotatable photosensitive drum 44 as animage carrier disposed almost at the center of the apparatus main body10. The outer surface of the photosensitive drum 44 is exposed to thelaser beam from the laser exposure apparatus 40, so a desiredelectrostatic latent image is formed. Around the photosensitive drum 44,a charger 45 for applying predetermined charges to the outer surface ofthe drum, a developing unit 46 for supplying toner as a developer to theelectrostatic latent image formed on the outer surface of thephotosensitive drum 44 to develop it at a desired image density, atransfer charger 48 which is integrated with a separation charger 47 forseparating a copy paper sheet P from the photosensitive drum 44 andtransfers the toner image formed on the photosensitive drum 44 to atransfer medium, i.e., the paper sheet P fed from a paper cassette (tobe described later), a separation gripper 49 for separating the copypaper sheet P from the outer surface of the photosensitive drum 44, acleaning unit 50 for removing toner remaining on the outer surface ofthe photosensitive drum 44, and a discharging unit 51 for dischargingthe outer surface of the photosensitive drum 44 are sequentiallyarranged.

An upper cassette 52, a middle cassette 53, and a lower cassette 54which can be pulled from the apparatus main body are stacked at thelower portion of the apparatus main body 10. These cassettes store copypaper sheets with different sizes. A large-capacity feeder 55 isarranged on one side of these cassettes. This large-capacity feeder 55stores about 300 copy paper sheets P having a size with high usefrequency, e.g., copy paper sheets P with A4 size. A feed cassette 57also serving as a manual feed tray 56 is detachably attached above thelarge-capacity feeder 55.

A convey path 58 extending from the cassettes and large-capacity feeder55 through a transfer section located between the photosensitive drum 44and transfer charger 48 is formed in the apparatus main body 10. Afixing unit 60 having a fixing lamp 60a is disposed at the end of theconvey path 58. A delivery port 61 is formed in the side wall of theapparatus main body 10 opposing the fixing unit 60. A single-trayfinisher 150 is attached to the delivery port 61.

Pickup rollers 63 for extracting the paper sheets P one by one from thecassette or large-capacity feeder are arranged near each of the uppercassette 52, middle cassette 53, lower cassette 54, and feed cassette 57and near the large-capacity feeder 55. A number of feed roller pairs 64for conveying the copy paper sheet P extracted by the pickup rollers 63through the convey path 58 are arranged in the convey path 58.

A resist roller pair 65 is arranged in the convey path 58 on theupstream side of the photosensitive drum 44. The resist roller pair 65corrects the tilt of the extracted copy paper sheet P, matches theleading edge of the toner image on the photosensitive drum 44 with theleading edge of the copy paper sheet P, and feeds the copy paper sheet Pto the transfer section at the same speed as the moving speed of theouter surface of the photosensitive drum 44. A prealigning sensor 66 fordetecting arrival of the copy paper sheet P is provided on the feedroller 64 side.

Paper sensors (not shown) for detecting paper jam (jam) are arranged atappropriate portions in the convey path in which the paper sheets P areextracted one by one from the cassette 52, 53, 54, or 75 or thelarge-capacity feeder 55 and delivered through the developing, transfer,and fixing units. If paper jam occurs, the conveyance operation isimmediately interrupted to cause the operator to recognize the paperjam.

Each copy paper sheet P extracted from the cassette or large-capacityfeeder 55 by the pickup rollers 63 is fed to the resist roller pair 65by the feed roller pair 64. After the leading edge of the copy papersheet P is aligned by the resist roller pair 65, the copy paper sheet Pis fed to the transfer section.

In the transfer section, a developer image, i.e., toner image formed onthe photosensitive drum 44 is transferred to the paper sheet P by thetransfer charger 48. The copy paper sheet P on which the toner image istransferred is separated from the outer surface of the photosensitivedrum 44 by the function of the separation charger 47 and separationgripper 49 and conveyed to the fixing unit 60 through a conveyor belt 67constituting part of the convey path 52. After the developer image isfused and fixed on the copy paper sheet P by the fixing unit 60, thecopy paper sheet P is delivered onto the finisher 150 through thedelivery port 61 by a feed roller pair 68 and a delivery roller pair 69.

An automatic double-side device 70 for reversing the copy paper sheet Pwhich has passed through the fixing unit 60 and feeding it to the resistroller pair 65 again is arranged under the convey path 58. The automaticdouble-side device 70 comprises a temporary stack 71 for temporarilystacking the copy paper sheets P, a reversing path 72 branched from theconvey path 58 to reverse the copy paper sheet P which has passedthrough the fixing unit 60 and guide the copy paper sheet P to thetemporary stack 71, pickup rollers 73 for extracting the copy papersheets P stacked on the temporary stack one by one, and a feed roller 75for feeding the extracted paper sheet to the resist roller pair 65through a convey path 74. A selector gate 76 for selectivelydistributing the copy paper sheets P to the delivery port 61 orreversing path 72 is arranged at the branch portion between the conveypath 58 and reversing path 72.

For double-side copying, the copy paper sheet P which has passed throughthe fixing unit 60 is guided to the reversing path 72 by the selectorgate 76, temporarily stacked on the temporary stack 71 in a reversedstate, and fed to the resist roller pair 65 through the convey path 74by the pickup rollers 73 and feed roller 75. The copy paper sheet P isaligned by the resist roller pair 65 and fed to the transfer sectionagain to transfer a toner image onto the blank surface of the copy papersheet P. After this, the copy paper sheet P is delivered to the finisher150 through the convey path 58, fixing unit 60, and delivery rollers 69.

The finisher 150 staples delivered copies of documents in units ofcopies. Every time a copy paper sheet P to be stapled is delivered fromthe delivery port 61, a guide bar 151 aligns the copy paper sheet P tothe stapling side. When all paper sheets are delivered, a copy of copypaper sheets P is pressed by a paper press arm 152 and stapled by astapler unit (not shown).

After this, the guide bar 151 moves downward. The stapled copy papersheets P are delivered to a finisher delivery tray 154 by a finisherdelivery roller 155 in units of copies. The downward moving amount ofthe finisher delivery tray 154 is roughly determined in accordance withthe number of copy paper sheets P to be delivered, so the finisherdelivery tray 154 moves downward stepwise every time one copy isdelivered. The guide bar 151 for aligning the delivered copy papersheets P is located at a position where the guide bar 151 does not abutagainst the already stapled copy paper sheets P placed on the finisherdelivery tray 154.

The finisher delivery tray 154 is connected to a shift mechanism (notshown) which shifts (e.g., in four directions: front, rear, left, andright sides) in units of copies in the sort mode. This shift mechanismis used to discriminate the delivery position of paper sheets printed ina memory full state for facsimile reception from that of copy papersheets which have already been printed by copying operation. Todiscriminate a copy output from a facsimile output, paper sheets may bedelivered in directions rotating through 90° with respect to each other.

An operation panel for inputting various copy conditions and a copystart signal for starting the copying operation is arranged at the upperportion on the front side of the apparatus main body 10. The indicatorsection and operation key arrangement of this operation panel will bedescribed with reference to FIG. 2.

FIG. 2 shows the arrangement of an operation panel 80 as an operationmeans. The operation panel 80 has a HELP key 146, an automatic paperselection key 131, an automatic magnification selection key 147, azoom/100% key 133, paper size keys 149, an LCD panel 135, a preheat key136, an interrupt key 137, an all clear key 150, a clear/stop key 139, astart key 140, a ten-key pad 141, a pause key 152, a total counterindicator 143, a clip tray 145, and the like.

Three indicators indicated by a circle D comprise an indicator D1 forindicating the copy state, an indicator D2 for indicating the presenceof a facsimile reception original, a communicating state, and an alarmoperating state, and an indicator D3 for indicating the presence ofprinter data and an alarm state, as shown in FIG. 3.

The LCD panel 135 indicates the set state of the operation mode of thecopying machine by blinking/displaying various characters and icons.

When the HELP key 146 is depressed as an operation guide key, a messagerepresenting the operation procedure is displayed on the LCD panel 135.When the HELP key 146 is depressed after functions are set, the setcontents can be confirmed on the LCD panel 135.

The automatic paper selection key 131 is normally set in an automaticpaper selection mode. The size of an original set on the original table(glass) 5 is automatically detected, and paper sheets having the samesize as that of the original are automatically selected (for only a copymagnification of ×1).

When the automatic magnification selection key 147 is depressed toselect an automatic magnification selection mode and set a desired papersize, the size of an original set on the original table (glass) 5 isdetected, and the copy magnification is automatically calculated.

When the “25%<” key at the left end of the zoom/100% key 133 isdepressed, the copy magnification decreases to 25% in units of 1%. Whenthe “>800%” key at the right end is depressed, the copy magnificationincreases to 800% in units of 1%. When the “100%”, key at the center isdepressed, the copy magnification returns to “×1” (100%).

The paper size key 149 is used to select a paper size.

The LCD panel 135 displays the state of the digital copying machine 1,operation procedure, and various instructions for the user as charactersand icons. The LCD panel 135 as a display means also incorporates atouch panel to allow function setting.

When the preheat key 136 is depressed, a preheat (power saving) mode isset, and all indicator lamps are turned off. To set the copy mode again,this button is depressed again.

The interrupt key 137 is used for an interrupt copy during continuouscopying or interrupt of a facsimile reception job and a copy job (to bedescribed later).

When the all clear key 150 is depressed, all selected modes are cleared,and the initial state is restored.

The clear/stop key 139 is used to correct the number of copies or stopthe copying operation.

The start key 140 is depressed to, e.g., start copying.

The ten-key pad 141 is used to set the number of copies. The number ofcopies can be set within the range of 1 to 999.

The pause key 152 is an operation button for inserting a pause betweendial inputs in ten-key input for the facsimile operation.

The total counter indicator 143 indicates the total copy volume aftermachine setting.

The clip tray 145 is a place where clips taken off from originals to becopied are placed and has a magnet.

The control circuit of the image forming apparatus shown in FIG. 1 willbe described next with reference to FIGS. 4 and 5.

FIG. 4 is a schematic view of the block diagram of the control system ofthe entire digital copying machine with a facsimile function shown inFIG. 1. FIG. 5 is a block diagram showing the detailed arrangement of abasic control section shown in FIG. 4.

As shown in FIG. 4, the control system of the digital copying machineroughly has two blocks and comprises a basic section 301 constructingthe basic configuration section of the digital copying machinecontrolled by a basic control section 311, in which the scanner section4 and printer section 6 are connected through an image processing means314, and a page memory section 302 for receiving and storing image datafrom the basic section 301 and transferring the stored image data againto the basic section 301 to realize memory copy (electronic sort).

The basic section 301 and page memory section 302 are connected througha basic section system interface 316 for transferring control data, anda basic section image interface 317 for transferring image data.

The basic section 301 comprises the scanner section 4 as an input means,printer section 6 as an output means, image processing means 314, andbasic control section 311 including a CPU as a control means forcontrolling the scanner and printer sections and image processing means.The above-described paper jam sensor sends a paper jam detection outputto a printer CPU (not shown) in the printer section 6. The printer CPUperforms processing for paper jam together with a main CPU (to bedescribed later) incorporated in the basic control section 311 inresponse to the sensor output. This paper jam processing will bedescribed later in detail.

As shown in FIG. 5, a main CPU 100 of the basic control section 311 isconnected to a ROM 102, a RAM 104, an image memory 106, an internalinterface 122, an external interface 123, a facsimile interface 126, aprinter interface 128, an auxiliary storage device interface 130, animage conversion circuit 132 for enlarging or reducing binary imagedata, and a compression/expansion circuit 134 for compressing orexpanding image data.

The image memory 106 is backed up by a battery 106B to prevent storedcontents from being lost in the power OFF state.

As shown in FIG. 6, the image memory 106 has a transmission/receptionmemory area 106-1 and an exclusive reception memory area 106-2 whichhave capacities of, e.g., 768 KB and 256 KB, respectively. Thetransmission/reception memory area 106-1 is used to, e.g., temporarilystore the image data of a transmission original document read by thescanner section 4 in a transmission reservation mode.

The exclusive reception memory area 106-2 is prepared to continuereception even when the transmission/reception memory area 106-1 becomesfull, and use of the exclusive reception memory area 106-2 is inhibitedin the transmission mode.

The internal interface 122 is connected to the above-described operationpanel 80. The external interface 123 is connected to an external device124. The facsimile interface 126 is connected to a public line 2 such asa telephone line. The printer interface 128 is connected to an externaldevice 138. The auxiliary storage device interface 130 is connected toan IC card reader/writer 142, a hard disk drive 144, and the like.

The facsimile interface 126 includes a modem for communication with thepublic line 2, an NCU as an interface for connection to the public line2, and the like.

In this arrangement, when image data of a document or the like is to betransmitted using the facsimile function, the main CPU 100 stores theimage data of a document read by the scanner section 4 in the imagememory 106. The stored image data is enlarged or reduced by the imageconversion circuit 132 as needed in accordance with the paper size atthe transmission destination. The image data whose size has beenconverted is coded by the compression/expansion circuit 134 and thentransmitted to the external device at the transmission destinationthrough the facsimile interface 126 and public line 2.

To receive image data from an external device using the facsimilefunction, a facsimile CFU (not shown) connected to the main CPU 100stores image data supplied from an external device at the transmissionsource through the public line 2 and facsimile interface 126 in theimage memory 106. The stored image data is decoded by thecompression/expansion circuit 134, stored in the image memory 106, andoutput to the printer section 6.

An image data storage/read for the copying operation is performed by themain CPU 100. For example, to store image data, image data read by thescanner section 4 is stored in the image memory 106 in accordance withan instruction from the main CPU 100. The main CPU 100 issues aninstruction in accordance with a mode determined by mode designation keyinput from the operation panel 80.

A parameter table 104 a is set in the RAM 104. The parameter table 104 astores various conditions set by key operations on the operation panel80. Default values stored in, e.g., the ROM 102 correspond to unsetconditions. Parameters to be set as conditions are image processingparameters in the copy mode, various setting conditions, ON/OFF of themagnification setting function, telephone numbers registered astransmission destinations, and the like.

The page memory section 302 will be described next with reference toFIG. 4. The page memory section 302 controls access from the basicsection 301 to a page memory (PM) 323. The page memory section 302comprises a system control means 304, the storage means (page memory)323 for temporarily storing image data, an address control section 306for generating an address of the page memory 323, an image bus 320 usedfor data transfer between the respective devices in the page memorysection 302, a control bus 321 used to control signal transfer betweenthe respective devices in the page memory section 302 and the systemcontrol means 304, a data control means 307 for controlling datatransfer in data transfer between the page memory 323 and another devicethrough the image bus 320, an image data interface (I/F) 308 forinterfacing image data in image data transfer between the basic section301 and page memory section 302 through the basic section imageinterface 317, a resolution conversion/binarization rotation means 325for, when image data is to be transmitted to a device with a differentresolution, converting the image data in accordance with the resolutionof this device, converting image data received from a device with adifferent resolution in accordance with the resolution of the printersection 6 of the basic section 301, or executing 90° rotation processingof binary image data, a compression/expansion means 324 for compressinginput image data for a device for compressing image data andtransmitting or storing it as in facsimile transmission or optical diskstorage, or expanding compressed image data to make it visible throughthe printer section 6, and a multilevel rotation memory 309 connected tothe image data I/F 308 and used to output the image data while rotatingit through 90° or −90°.

Like the image memory 106, the page memory 323 is backed up by a battery323B. Instead the battery 323B, the battery 106B for the image memory106 may be used such that the two memories are backed up by a commonbattery.

The facsimile reception operation of the image forming apparatus with afacsimile function having the above arrangement will be described indetail with reference to FIGS. 6 to 13.

When the facsimile reception mode is set by operation on the operationpanel 80, and a facsimile signal is received from an external devicethrough the public line 2, memory reception start processing (ST1) inFIG. 7 is executed.

With this processing, the modem is set in ST11 in FIG. 10. The facsimilesignal is demodulated by a modem incorporated in the facsimile interface126 and received by the image memory 106 in FIG. 5 (ST12).

It is checked whether the image memory 106 still has a capacity (ST13).If YES in ST13, reception is continued (ST12). When the reception stateis ended (ST15), the user is notified of the end of reception (ST17).

If it is determined in ST13 that the image memory 106 has no remainingcapacity, the flow advances to ST21 to end the processing.

The facsimile signal received in this way is stored in the image memory106 as compressed data.

Referring back to the flow in FIG. 7, when the start of memory reception(ST1) is ended, the remaining capacity of the image memory 106 isconfirmed in the next step ST2. If the memory is not full, the flowadvances from step ST3 to ST4 to check whether reception is ended. IfYES in ST4, the flow advances to ST5 to start transfer processing fromthe image memory 106 to the page memory 323 for image data printing(ST6).

This transfer processing from the image memory 106 to the page memory323 for image data printing will be described with reference to FIG. 11.

First, in step ST51, compressed data in the image memory 106 is expandedby the compression/expansion means 324 and transferred to the pagememory 323 as raw data. At this time, the memory full state of the imagememory 106 is monitored (ST52). If the memory is not full, it is checkedin step ST53 whether transfer of one page is complete. If transfer iscomplete, a transfer completion notification is output, and processingis ended (ST54).

When the memory full state is detected in step ST52, a memory block ofthe image memory 106 where transfer is complete is changed to anoverwritable state (ST55). The flow advances to step ST53 to checkcompletion of transfer of one page.

The operation in FIG. 11 will be described in more detail with referenceto FIGS. 9A to 9C. Referring to FIG. 9A, reception image data is alreadystored in an area A1 of the exclusive reception memory area 106-2 of theimage memory 106 while there is little free area A2, so the memory fullstate is detected in step ST52.

In this state, the image data indicated by a broken line at the end ofthe area Al is block-transferred to the free area of the page memory 323shown in FIG. 9B. As a result, as shown in FIG. 9C, an area A3 where theoverwrite is enabled by data transfer to the page memory 323 is formedin the exclusive reception memory area 106-2 of the image memory 106.

The image data in the area A3 is lost when image data from an externaldevice is overwritten, though image identical to the lost data hasalready been transferred to the page memory 323. Since this page memory323 is backed up by the battery 323B, the image data is held in the pagememory 323 without being lost even when the power is turned off in thisstate.

In this way, when image data transfer processing (ST5) from the imagememory 106 to the page memory 323 is started, it is checked in step ST6in FIG. 7 whether transfer is complete. If complete of transfer isdetected, the next printing processing is driven (ST7).

In printing processing, as shown in FIG. 12, the image data stored inthe page memory 323 is sent from the data control means 307 to the imagedata I/F 308 through the image bus 320 and then sent to the printersection 6 to execute printing processing (ST71).

The image data is sent from the image memory 106 to the page memory 323in units of blocks and sequentially printed. Completion of printing anddelivery of printed paper sheets are checked in step ST72. If printingis complete, a printing completion notification is output (ST73).

If it is determined in ST72 that delivery of paper sheets is notcomplete, it is checked in ST74 whether paper jam (jam) has occurred. IfNO in ST74, the flow returns to ST72. If YES in ST74, jam notificationprocessing for the operator is performed in ST75, and processing isended.

If it is determined in the flow in FIG. 7 that printing is not complete(ST72), a jam is checked in ST74. If YES in ST74, it is checked whetherjam cancel processing has been performed by the operator in response tojam notification processing for the operator in ST75 (ST76). Aftercancel, the flow returns to printing start processing in ST7.

When completion of printing is detected (ST72), it is checked whetherimage data still remains in the image memory 106 (ST8). If no image dataremains, the reception file is deleted from the image memory 106 (ST9),and processing is ended.

When completion of printing is detected in ST72, the printing completionnotification is sent to the main CPU 100, and the image data sent fromthe image memory 106 to the page memory 323 in units of blocks isfinally erased from the page memory 323. Even when data transfer stopsmidway due to paper jam or the like when the image data stored in thepage memory 323 is being sent to the printer section 6, the block datastored in the page memory 323 is held in the page memory 323 untilprinting is complete. Hence, when the paper jam is eliminated, printingcan be satisfactorily continued by sending the block data stored in thepage memory 323 to the printer section 6 again.

When the memory full state is detected in step ST3 before reception iscomplete, the flow advances to ST10 in FIG. 8 to start image datatransfer processing from the image memory 106 to the page memory 323.This transfer processing has the same contents as in step ST5.

When completion of transfer is detected (ST100), printing processing isstarted, as in step ST7 (ST111).

If overflow of the image memory 106 is detected in ST110 before transferis complete, memory over processing is executed (ST120).

This memory over processing will be described in detail with referenceto FIG. 13. When overflow of the image memory 106 occurs in the memoryfull state, processing of forcibly ending communication is performed instep ST121. As a consequence, an error signal is sent from, e.g., thepublic line 2 to the device at the transmission source.

After this, processing of transferring already received image data inthe image memory 106 to the page memory 323 is started (ST122). Thisimage transfer start processing has already been described inassociation with step ST5 or ST10, and a detailed description thereofwill be omitted.

Completion of transfer is checked in ST123. If YES in ST123, printingprocessing is started in the next step ST124. This printing processinghas also already been described in association with step ST7.

Subsequently, completion of printing is checked in step ST125. If YES inST125, it is checked in step ST126 whether data still remains in theimage memory 106. If data remains, the flow returns to step ST122 tocontinue image transfer. If no data remains, the flow advances to step127 to delete the reception file from the image memory 106, andprocessing is ended.

If completion of printing is not detected in step ST125, it is checkedin ST128 whether jam has occurred. If no jam has occurred, the flowreturns to ST124. If jam has occurred, the flow advances to ST129 tocheck whether jam cancel processing by the operator has been performed.When jam has been canceled, the flow returns to printing startprocessing (ST124).

Referring back to FIG. 8, printing processing is started in step ST111.It is checked whether printing is complete (ST112). Before completion,jam occurrence is checked in step ST131. If no jam has occurred, it ismonitored in step ST113 whether the image memory 106 is in the overflowstate.

In the overflow state, the flow advances to step ST114 to execute memoryoverflow processing as in step ST120.

When it is detected in step ST131 that jam has occurred, it is checkedin the next step ST132 whether jam cancel processing is complete. If YESin ST132, the flow returns to printing start processing (ST111).

Before jam cancel is complete, the memory over state of the image memory106 is checked in ST133. If the memory over state is not detected,monitoring is continued until jam cancel is complete in ST132. In thememory over state, the flow advances to ST134 to execute memory overprocessing.

If it is detected in step ST112 that printing is complete, it is checkedin ST115 whether data still remains in the image memory 106. If NO inST115, it is checked whether reception is complete (ST116). If YES inST116, the flow advances to step 117 to delete the reception file fromthe image memory 106, and processing is ended.

In the above description, when the memory full state is detected duringfacsimile reception, a printing start request is issued. At this time,if paper jam, i.e., jam has occurred, processing is executed whiledetermining that printing is disabled. However, the facsimile receptionprinting disable state is determined not only based on paper jam butalso when the printer is already performing the copying operation.

In the present invention, a composite image forming apparatus isconstructed such that even when the facsimile reception printing disablestate is determined because the printer is already performing thecopying operation, facsimile reception printing can be started, and evenwhen the memory full state is detected during facsimile reception, thefacsimile reception can be continued without immediately disconnectingthe line. An embodiment thereof will be described below with referenceto FIGS. 14 to 17.

When the image forming apparatus is set in the facsimile reception mode,memory reception by a reception image memory formed from the imagememory 106 is continued in ST140 in FIG. 14. In this state, it iscontinuously checked in ST141 whether the remaining memory capacity hasa predetermined value or less, i.e., exceeds a predetermined memory fullprinting start threshold value. If YES in ST141, the flow advances toST142, and a printing start request is output from the facsimile CPU tothe printer CPU.

The operation flow of the facsimile CPU will be described with referenceto FIG. 15. Referring to FIG. 15, when the facsimile reception mode isset in ST160, reception of a facsimile signal is started in ST161, andthe memory reception operation is executed in ST162.

In this state, the memory full state is monitored in ST163. If thememory full state is detected, a printing request for the printer isissued in ST164. This printing request is sent to the printer CPU. Asshown in FIG. 16, the printer CPU checks in ST170 whether a printingrequest is present. If YES in ST170, this request is recorded in aprinting queue for sequentially storing printing requests in ST171.

Referring back to FIG. 15, even after the printing request is issued inST164, memory reception is continuously performed in ST165 independentlyof the result of the printing request. The memory over state is checkedin ST166. If the memory over state is detected, the line is disconnectedin ST167. If no memory over state is detected, and completion ofreception is detected in ST168, the facsimile reception is normallyended in ST169.

The operation flow of the printer CPU will be described with referenceto FIG. 17. The printer CPU checks in ST180 whether a printing requestis present in the printing queue described with reference to FIG. 16. IfYES in ST180, it is checked in ST181 whether printing can be performed.If YES in ST181, a printing start operation is performed in ST182.

After the start of printing, errors such as paper jam are monitored inST183. If YES in ST183, the above-described error processing is executedin ST184. If NO in ST183, the flow returns to ST180 to check whether thenext printing request is present. If YES in ST180, the processing iscontinued.

Referring back to FIG. 14, when a printing request is issued in ST142,it is checked in ST143 whether paper jam has occurred at that time. Ifpaper jam has occurred, the remaining memory capacity is checked inST144. If the memory capacity remains, memory reception is continued inST145. If no memory capacity remains, line disconnection processing isexecuted in ST146, as described with reference to FIG. 15.

When a printing request is issued, and it is determined in ST143 that nopaper jam has occurred, and printing can be normally performed, it ischecked in ST147 whether the copying operation is being performed. If NOin ST147, facsimile reception printing is started in ST148.

If YES in ST147, it is checked in ST149 whether a copying operationinterruption function is present. If YES in ST149, an interrupt isautomatically generated to interrupt the copying operation in ST150.Facsimile reception printing is started in ST151. This interrupt isautomatically started. Alternatively, a message for asking the operatorfor the interruption of copying operation is displayed on the displayscreen 135 of the operation panel 80, and an interrupt is generated inresponse to the operator's operation of the interrupt key 137. Whenfacsimile reception printing is complete in ST151, the interrupt isended, and the interrupted copying operation is resumed.

If it is determined in ST149 that no interruption function is present,operations of checking the memory full state, disconnecting the line,and the like are performed in ST152, ST153, and ST154, as in ST144 toST146.

As has been described above in detail, according to the presentinvention, when a memory full state is detected during facsimilereception, a reception image printing request is issued. It is detectedwhether paper jam has occurred or the copying operation is beingperformed. During the copying operation, the facsimile reception imageis preferentially printed by an interrupt. With this arrangement, thereception image memory rarely becomes full during facsimile reception,and printing can be continued without disconnecting the like. Hence, aconvenient image forming apparatus can be provided.

What is claimed is:
 1. An image forming apparatus characterized bycomprising: a reception image memory for storing reception image data;means for checking whether a printing operation using the receptionimage data stored in said reception image memory can be started when aremaining capacity of said reception image memory has not more than apredetermined value; means for starting printing using the receptionimage data when it is determined by said checking means that printing ispossible; means for, when a printing disable state is detected by saidchecking means, displaying the printing disable state and checkingwhether a cause is paper jam; and means for, when the cause is paperjam, causing said reception image memory to continuously receive andstore the reception image data.
 2. An image forming apparatuscharacterized by comprising: a reception image memory for storingreception image data; means for checking whether a printing operationusing the reception image data stored in said reception image memory canbe started when a remaining capacity of said reception image memory hasnot more than a predetermined value; means for starting printing usingthe reception image data when it is determined by said checking meansthat printing is possible; means for, when a printing disable state isdetected by said checking means, displaying the printing disable stateand checking whether a cause is paper jam or an operation of copyingmeans; means for, when the cause is paper jam, causing said receptionimage memory to continuously receive and store the reception image data;determination means for, when the cause is the operation of said copyingmeans, determining whether the operation can be stopped; interruptiondesignation means for, when said determination means determines that theoperation can be stopped, designating interruption; and means forprinting the reception image data in response to designatedinterruption.
 3. An image forming apparatus according to claim 2,characterized by further comprising a tray for receiving a copy papersheet formed during copying, and means for outputting a reception imageprinting paper sheet formed in response to the designated interruptionto a position discriminated from that of the copy paper sheet.
 4. Animage forming apparatus according to claim 2, characterized in that saidcopying means comprises a copy image memory for storing copy image data,means for sequentially reading out the stored copy image data in unitsof page data, a page memory for storing the page data thus read out,printing means for printing the page data stored in said page memory,and means for overwriting an area where the page data is partially readout from said image memory to said page memory as a free area of saidcopy image memory, and that said interrupting means includes means forinterrupting the operation when printing of the page data stored in saidpage memory is completed.
 5. An image forming apparatus according toclaim 4, characterized in that said reception image data printing meanscomprises control means having means for switching an image memory areawhere the image data is read out from said reception image memory froman overwrite disable state to an overwrite enable state when theremaining capacity of said reception image memory has not more than apredetermined value, confirmation means for conforming that printing ofthe page data stored in said page memory is completed, and means for, inresponse to a confirmation output from said confirmation means,transferring the next page data from said reception image memory to saidpage memory.
 6. An image forming apparatus according to claim 4,characterized in that said control means comprises detection means fordetecting paper jam in said printing means, means for holding the pagedata stored in said page memory in accordance with an output from saiddetection means, means for detecting elimination of the paper jam, meansfor continuing to print the page data stored in said page memory inresponse to the elimination, confirmation means for confirmingcompletion of printing of the page data, and means for transferring thenext page data from said image memory to said page memory upon receivinga confirmation output from said confirmation means.
 7. An image formingapparatus characterized by comprising: a reception image memory forstoring reception image data; means for checking whether a printingoperation using the reception image data stored in said reception imagememory can be started when a remaining capacity of said reception imagememory has not more than a predetermined value; means for startingprinting using the reception image data when it is determined by saidchecking means that printing is possible; means for, when a printingdisable state is detected by said checking means, displaying theprinting disable state and checking whether a cause is paper jam or anoperation of copying means; means for, when the cause is paper jam,causing said reception image memory to continuously receive and storethe reception image data; interruption designation means for, when thecause is the operation of said copying means, designating interruption;means for printing the reception image data in response to theinterruption designated; and means for causing said copying means tocontinue interrupted printing when printing of the reception image datais completed.
 8. An image forming apparatus in an image datatransmission/reception system including first and second apparatuseshaving reading means, connected to each other through a communicationline, for reading originals and converting originals signal into imagedata, transmission means for transmitting image data read from theoriginals, reception means for receiving the image data, and imageforming means for forming images of the image data on target imageforming medium, characterized in that each of said first and secondapparatuses comprises: a reception image memory for storing receptionimage data; means for checking whether a printing operation using thereception image data stored in said reception image memory can bestarted when a remaining capacity of said reception image memory has notmore than a predetermined value; means for starting printing using thereception image data when it is determined by said checking means thatprinting is possible; means for, when a printing disable state isdetected by said checking means, displaying the printing disable stateand checking whether a cause is paper jam or an operation of copyingmeans; and means for, when the cause is paper jam, causing saidreception image memory to continuously receive and store the receptionimage data.
 9. An image forming apparatus according to claim 8,characterized in that said reception image data printing means comprisescontrol means having means for switching an image memory area where theimage data is read out from said reception image memory from anoverwrite disable state to an overwrite enable state when the remainingcapacity of said reception image memory has not more than apredetermined value, confirmation means for conforming that printing ofthe page data stored in said page memory is completed, and means for, inresponse to a confirmation output from said confirmation means,transferring next page data from said reception image memory to saidpage memory.
 10. An image forming apparatus according to claim 9,characterized in that said control means comprises detection means fordetecting paper jam in said printing means, means for holding page datastored in said page memory in accordance with an output from saiddetection means, means for detecting elimination of the paper jam, meansfor continuing to print the page data stored in said page memory inresponse to the elimination, confirmation means for confirmingcompletion of printing of the page data, and means for transferring thenext page data from said image memory to said page memory upon receivinga confirmation output from said confirmation means.
 11. An image formingapparatus in an image data transmission/reception system including firstand second apparatuses having reading means, connected to each otherthrough a communication line, for reading originals and converting aread originals signal into image data, transmission means fortransmitting the image data read from the originals, reception means forreceiving the image data transmitted, and image forming means forforming images of the image data on target image forming medium,characterized in that each of said first and second apparatusescomprises: a reception image memory for storing reception image data;means for checking whether a printing operation using the receptionimage data stored in said reception image memory can be started when aremaining capacity of said reception image memory has not more than apredetermined value; means for starting printing using the receptionimage data when it is determined by said checking means that printing ispossible; means for, when a printing disable state is detected by saidchecking means, displaying the printing disable state and checkingwhether a cause is paper jam or an operation of copying means; meansfor, when the cause is paper jam, causing said reception image memory tocontinuously receive and store the reception image data; interruptiondesignation means for, when the cause is the operation of said copyingmeans, designating interruption; and means for printing the receptionimage data in response to the interruption designated.
 12. An imageforming apparatus according to claim 11, characterized in that saidreception image data printing means comprises control means having meansfor switching an image memory area where the image data is read out fromsaid reception image memory from an overwrite disable state to anoverwrite enable state when the remaining capacity of said receptionimage memory has not more than a predetermined value, confirmation meansfor conforming that printing of the page data stored in said page memoryis completed, and means for, in response to a confirmation output fromsaid confirmation means, transferring next page data from said receptionimage memory to said page memory.
 13. An image forming apparatusaccording to claim 12, characterized in that said control meanscomprises confirmation means for confirming completion of printing ofpage data stored in said page memory, and means for transferring thenext page data from said image memory to said page memory upon receivinga confirmation output from said confirmation means.
 14. An image formingapparatus according to claim 12, characterized in that said controlmeans comprises detection means for detecting paper jam in said printingmeans, means for holding the page data stored in said page memory inaccordance with an output from said detection means, means for detectingelimination of the paper jam, means for continuing to print the pagedata stored in said page memory in response to the elimination,confirmation means for confirming completion of printing of the pagedata, and means for transferring the next page data from said imagememory to said page memory upon receiving a confirmation output fromsaid confirmation means.